T4 2020 auto fill is different than manual calculation.

I was waiting to complete the 2020 T4s until the update arrived with the auto fill option, hoping to not make any mistakes.  

When I reviewed the information I was concerned the numbers that automatically came up were different from the manual calculations.  I discovered this was due to commissions not being included in the automatic calculations but are included when I run a PD7A report.

I spent approx 2 hours on hold with CRA to get clarification and while the agent agreed they should be part of the calculation, they are escalating the inquiry to get further clarification as it was not their first call regarding third party software calculating incorrect totals and the online information was not specific.

Is there a reason commissions should not be included as part of the employment income in box 57,58,59 &60?